321-68-6Relevant academic research and scientific papers
Electrochemical Palladium-Catalyzed Intramolecular C—H Amination of 2-Amidobiaryls for Synthesis of Carbazoles
Gao, Xinlong,Lei, Aiwen,Wang, Pan,Wang, Qingqing,Zhang, Heng,Zhang, Xiaojing
supporting information, p. 143 - 148 (2020/12/18)
The synthesis of carbazoles based on the electrochemical Pd-catalyzed intramolecular C—H amination of 2-amidobiaryls through oxidative cross coupling has been achieved under mild reaction conditions. The reaction can be carried out in undivided cell without the addition of external chemical oxidant. Besides good functional group compatibility, the desired carbazoles can be scaled up and modified easily. Compared with previous methods, this protocol affords a simple and sustainable avenue for the construction of carbazoles.
Synthesis of Fluorescent 4-Azapyrenes by Palladium(II)-Catalyzed Dual C?H Bond Activation and Annulation
Hsiao, Huan-Chang,Annamalai, Pratheepkumar,Jayakumar, Jayachandran,Sun, Shang-You,Chuang, Shih-Ching
supporting information, p. 1695 - 1701 (2021/02/12)
Unique dual-emissive and deep-blue/green fluorescent multi-substituted 4-azapyrenes with bathochromic shift emission, quantum yields up to 0.60 and long excited-state lifetime were synthesized successfully by annulative π-extension reactions. This synthesis constitutes a palladium-catalyzed dehydrogenative annulation of N-acyl-2-aminobiaryls with in situ 1,3-diynes as a key step, giving substituted phenanthrenes via a rollover C?H bond activation, followed by Bischler-Napieralski cyclization. Further π-extension by superacid-mediated cyclization produced a blue fluorescent naphtho 4-azapyrene. (Figure presented.).
Photocatalytic xanthate-based radical addition/cyclization reaction sequence toward 2-biphenyl isocyanides: Synthesis of 6-alkylated phenanthridines
López-Mendoza, Pedro,Miranda, Luis D.
supporting information, p. 3487 - 3491 (2020/05/25)
A photocatalytic xanthate-based radical addition/cyclization reaction cascade toward 2-biphenylisocyanides is described as a practical and modular approach to 6-alkylated phenanthridines. The use of xanthates as radical precursors allowed the synthesis of diversely 6-substituted phenanthridines. Electrophilic radicals derived from nitriles, aromatic and aliphatic ketones, malonates, and amide derivatives, as well as radicals derived from phthalimidomethyl and benzylic derivatives were successfully introduced. The reaction proceeds under mild conditions without a stoichiometric amount of oxidant. Thirty novel phenanthridine scaffolds were synthesized with yields ranging from 24 to 76%.
Visible-Light-Driven Difluoromethylation of Isocyanides with S-(Difluoromethyl)diarylsulfonium Salt: Access to a Wide Variety of Difluoromethylated Phenanthridines and Isoquinolines
Chen, Jia-Yi,Li, Xin,Lin, Li-Ting,Liu, Guo-Kai,Qin, Wen-Bing,Wong, Henry N. C.,Xiong, Wei
, p. 10479 - 10487 (2020/09/23)
A highly efficient approach of visible-light-driven radical difluoromethylation of isocyanides to access a wide variety of difluoromethylated phenanthridines and isoquinolines is herein described. Electrophilic S-(difluoromethyl)diarylsulfonium salt proved to be a good difluoromethyl radical precursor under photoredox catalysis. A broad range of isocyanides were tolerated to furnish the corresponding difluoromethylated phenanthridines, isoquinolines, furo[3,2-c]pyridine, and pyrido[3,4-b]indole in moderate to excellent yields under mild conditions. A plausible mechanism was also proposed.
NBE-Controlled Palladium-Catalyzed Interannular Selective C-H Silylation: Access to Divergent Silicon-Containing 1,1′-Biaryl-2-Acetamides
Li, Wenguang,Chen, Wenqi,Zhou, Bang,Xu, Yankun,Deng, Guobo,Liang, Yun,Yang, Yuan
supporting information, p. 2718 - 2722 (2019/04/16)
A novel palladium-catalyzed interannular selective C-H silylation of 1,1′-biaryl-2-acetamides is described. The combination of palladium catalyst with copper oxidant enables meta- or ortho-selective C-H silylation by employing hexamethyldisilane as a trimethylsilyl source, which relies on the control of NBE derivatives as a switch, thus providing straightforward access to divergent silicon-containing 1,1′-biaryl-2-acetamides.
Radical (Phenylsulfonyl)difluoromethylation of Isocyanides with PhSO2CF2H under Transition-Metal-Free Conditions
Xiao, Pan,Rong, Jian,Ni, Chuanfa,Guo, Junkai,Li, Xinjin,Chen, Dingben,Hu, Jinbo
supporting information, p. 5912 - 5915 (2016/11/29)
An atom-economical method for radical (phenylsulfonyl)difluoromethylation of isocyanides with PhSO2CF2H under transition-metal-free conditions has been developed. A PhSO2CF2 radical is generated through the oxidation of PhSO2CF2- after the deprotonation of PhSO2CF2H in one pot. The reaction exhibits excellent functional-group tolerance and the resulting products can be further modified with the removal of a PhSO2 group to give other CF2-containing compounds.
Radical Fluoroalkylation of Isocyanides with Fluorinated Sulfones by Visible-Light Photoredox Catalysis
Rong, Jian,Deng, Ling,Tan, Ping,Ni, Chuanfa,Gu, Yucheng,Hu, Jinbo
supporting information, p. 2743 - 2747 (2016/02/26)
The radical fluoroalkylation of isocyanides with fluorinated sulfones is enabled by visible-light photoredox catalysis. A wide range of readily available mono-, di-, and trifluoromethyl heteroaryl sulfones can thus be used as efficient radical fluoroalkylation reagents under mild conditions. This method not only describes a new synthetic application of fluorinated sulfones, but also provides a new route to fluoroalkyl radicals.
Transition-metal-free synthesis of phenanthridinones from biaryl-2-oxamic acid under radical conditions
Yuan, Ming,Chen, Li,Wang, Junwei,Chen, Shenjie,Wang, Kongchao,Xue, Yongbo,Yao, Guangmin,Luo, Zengwei,Zhang, Yonghui
supporting information, p. 346 - 349 (2015/02/19)
Na2S2O8-promoted decarboxylative cyclization of biaryl-2-oxamic acid for phenanthridinones has been developed. This work illustrates the first example of intramolecular decarboxylative amidation of unactivated arene under transition-metal-free conditions. Additionally, this approach provides an efficient and economical method to access biologically interesting phenanthridinones, an important structure motif in many natural products. (Chemical Equation Presented).
Synthesis of phenanthridine derivatives via cascade annulation of diaryliodonium salts and nitriles
Li, Jian,Wang, Hongni,Sun, Jiangtao,Yang, Yang,Liu, Li
supporting information, p. 7904 - 7908 (2014/12/12)
A cascade coupling reaction toward a variety of phenanthridine derivatives has been developed. This cascade transformation proceeds via the copper-catalyzed coupling reaction of diaryliodonium salts and nitriles, and undergoes cyclization into the phenanthridine core.
Transition-metal-free direct arylation of anilines
Pirali, Tracey,Zhang, Fengzhi,Miller, Anna H.,Head, Jenna L.,McAusland, Donald,Greaney, Michael F.
supporting information; experimental part, p. 1006 - 1009 (2012/02/16)
Aryne arylation: A new method of direct arylation is reported for aniline substrates. The reaction uses benzyne to synthesize a variety of aminobiaryls under mild conditions (see scheme), requiring no stoichiometric metalation or transition-metal catalysis. An ene mechanism is implicated, and conveys excellent functional group tolerance relative to metal-mediated processes. Copyright
